Lamp



FIG. 1 is a perspective front view of a lamp showing my new design;

FIG. 2 is a front elevational view thereof, the rear being a mirror image;

FIG. 3 is a right side view thereof, the left side being a mirror image; and,

FIG. 4 is a top plan view thereof.

The broken line showing of environmental structure is for illustrative purposes and does not form a part of the claimed design. 

The ornamental design for a lamp, substantially as shown and described. 